Also Known As: Conjugated Estrogens, Premarin
Premarin is the commercial name for a compound cream of vaginally administered estrogens, consisting primarily of conjugated estrogens. Isolated from mares' urine (PREgnant MARes' urINe), it is manufactured by Wyeth Pharmaceuticals (part of Pfizer since January 2009) and has been marketed since 1942. It is available in oral (0.3/ 0.45/ 0.625/ 0.9/ 1.25 mg), IV, and topical form.
Premarin is a form of hormone replacement therapy. Premarin pills are used most commonly in post menopausal women who have had a hysterectomy to treat hot flashes, and burning, itching, and dryness of the vagina and surrounding areas. It can also be used in conjunction with a progestin pill in women who have not had a hysterectomy. For women already taking the drug it can be used to treat osteoporosis, although it is not recommended solely for this use. The most common side effects associated with Premarin use are vaginal yeast infections, vaginal spotting or bleeding, painful menses, and cramping of the legs.
While there are some contradictory data, estrogen alone does not appear to increase the risk of coronary heart disease or breast cancer, like estrogen with progestin does. While estrogen alone appears to decrease the risk of hip fracture for women who have had a hysterectomy, it is still suggested that Premarin be used for the shortest period of time and at the smallest possible dose that is effective in alleviating symptoms because it can increase the risk of endometrial cancer, stroke, blood clots, and possibly dementia. Premarin cream is only used for vaginal burning, dryness and itching.
Some of Premarin’s lesser known uses are the treatment of symptoms associated with metastatic breast cancer in men and women and prostate cancer in men. It can also be used for individuals that do not produce enough estrogen due to hypogonadism, castration, and ovarian failure, or who have certain intersex conditions such as Androgen insensitivity syndrome.